While on stage at the 1999 Video Music Awards, the Detroit rocker played a nimble game of microphone toss with Steven Tyler and performed a medley of songs with the Aerosmith singer, fellow Toxic Twin Joe Perry and the iconic hip-hop act Run-DMC.

that he thinks Tyler's new gig as a judge on "American Idol" is a big mistake.

"I think it's the stupidest thing he's ever done in his life," he told the magazine. "He's a sacred American institution of rock and roll, and he just threw it all out the window. Just stomped on it and set it on fire."

Tyler, who surprised "Idol" fans — and his own bandmates — with the move to his first TV gig, has mostly been mum about why he decided to join Jennifer Lopez and Randy Jackson on the show's new-look judging panel. While reaction from the rock community regarding the 62-year-old's late-career about-face has mostly been muted, Rock did not mince words.

"I think whoever's advising him ... we should bring back the guillotine, or whatever they call that thing," he said. "And if it was himself, he needs some serious counseling. I love him to death, but I gotta speak the truth."

By contrast, Tyler appeared very pumped-up for the gig when the worst-kept secret in broadcasting was finally revealed last month. "It's being a part of something much bigger than yourself," Tyler said to "Idol" host Ryan Seacrest. "I want to bring some rock to this roller coaster and show you that if you got the heart, you got the talent and you got the feeling to do this, you could be the next American Idol."